I use MPEG Streamclip, a free high quality converter for MPEG files, Quicktime and transport streams on my Macs. It can export to Quicktime, DVI, AVI, MPEG-4, etc. and has a robust editor to trim video.
OK, well have fun with that then. Good luck on your project.
And for talking up, Media Composer | First, Lightworks, Davinci Resolve will also all definitely do the job. You could also use a 15 or 30 day demo of just about any editor you choose to use to get this single clip sliced up.
Also, Handbrake, Streamclip, etc. are based on ffmpeg. ffmpeg can be used to chop up clips, but without a GUI you'll need to know what you are doing with the command line arguments. There are a lot of tools out there based on ffmpeg, including some that are used for high level professional use. VLC uses ffmpeg for some of its work, but not exclusively like Streamclip and Handbrake.